Visible crew/equipment: After Matthew meets with the Mayor's Special Assistant and told to keep it quiet, it soon cuts to Mathew inside a phone booth to make a call. As the camera moves around the booth you can see a reflection of the cameraman. (01:05:35)
Revealing mistake: Near the end of the film when Matthew is trying to destroy the pod "greenhouse," there is a shot where Elizabeth walks through. She is supposed to be naked, but if you look close you can see she is wearing flesh colored underwear. (01:55:30)
Other mistake: In every case, the pod needs hours to take over the human, but, in Elizabeth's case, she gets changed in less than 5 minutes. (01:24:00)
Visible crew/equipment: After Matthew and Elizabeth take the pills to stay awake, when they are found Matthew shouts, "David, don't let them touch her," and there's a visible T-mark taped to the floor in the overhead shot. (01:31:30)
Continuity mistake: When Matthew goes to rescue Elizabeth from her boyfriend he parks on the street. When they leave he is parked in the driveway.
Answer: On the DVD commentary, Director Phillip Kaufman explained that the leather on Nimoy's hand was the actor's idea and simply showed how kooky the character was. Fits the character well really.
Gavin Jackson